Event horizons in worldbuilding: Worm

Something I notice about Worm in retrospect that is really clever is that it has this "event horizon" in its history. It's like Earth, and everything is normal... up until this event horizon where superpowers appear and everything changes.

This is a really clever idea. By having superpowers appear only some way into history, Wildbow doesn't have to imagine everything that would go different from the dawn of time because of superpowers. Wildbow only has to figure out everything that would go different starting from, say, 1970. (I don't actually remember when Worm's event horizon is, and I'm not going to look it up.) That changes the job of worldbuilding from "impossible, multiple people worth of work to do it justice" to "okay, that seems kind of doable."

It matters that in Worm the world is Earth plus some changes. For other kinds of world it seems less necessary, although it could still be an interesting option depending on the kind of story you're telling. But this event horizon trick seems really useful for the Earth-plus-changes kind of world.